Protective clothing for an operator working in a hermetic enclosure

ABSTRACT

The invention is concerned with improvements in protective clothing for use by an operator working in a hermetic enclosure which is at a positive pressure to the ambient atmosphere. The clothing comprises a hermetic garment which has two walls which define an inflatable zone the inner wall being in contact with the operator and the outer wall forming part of the enclosure wall. A permanent leak is provided from the inflatable zone to the inside of the protective clothing by way of permeable means disposed on the inner wall. Means is also provided for permitting and adjusting the rate of leakage flow from inside the protective clothing either to the ambient atmosphere or to the inside of the hermetic enclosure.

United States Patent 1 1 Saint-Martin Nov. 6, 1973 PROTECTIVE CLOTHINGFOR AN OPERATOR WORKING IN A HERMETIC ENCLOSURE [75] Inventor: [73]Assignee: La Calhene, Bezons, France [22] Filed: Apr. 14, 1972 [21]Appl. No.: 243,933

Bernard Saint-Martin, Paris, France 52 us. c1. 128/1425 [51] Int. ClA611) 19/00 [58] Field of Search 128/142.S, 1 A, 142.4,

128/142.7, 297, 298, 204,l32,134,1 R, 1 B; 312/1, 3, 4; 2/21 R, 2.1 A

{56] 1 References Cited UNITED STATES PATENTS 3,670,718 6/1972 Brendgord128/1 R 1,226,148 5/1917 Walters l28/l42.5 3,439,966 4/1969 Perkins etal. 128/1 R 3,158,149 11/1964 Gray 128/1 A 3,355,230 11/1967 Trexler128/1 R Primary Examiner-Richard A. Gaudet Assistant ExaminerHenry .I.Recla Attorney-William B. Kerkam, Jr.

[57] ABSTRACT The invention is concerned with improvements in protectiveclothing for use by an operator working in a hermetic enclosure which isat a positive pressure to the ambient atmosphere. The'clothing comprisesa hermetic garment which has two walls which define an inflatable zonethe inner wall being in contact with the operator and the outer wallforming part of the enclosure wall. A permanent leak is provided fromthe inflatable zone to the inside of the protective clothing by way ofpermeable means disposed on the inner wall. Means is also provided forpermitting and adjusting the rate of leakage flow from inside theprotective clothing either 7 to the ambient atmosphere or to the insideof the hermetic enclosure.

10 Claims, 4 Drawing Figures PATENTEDunv 61915 3,769,972

SHEET 10F 3 FIG] PATENTED NUV 6 I973 sum 3 BF 3 FIG.

FIGA

Y 1 PROTECTIVE CLOTHING FOR ANOPERATOR WORKING IN A HERMETIC ENCLOSUREThis invention relates to protective clothing for protecting an operatorwho has to work in a hermetic enclosure or chamber or the like.

Various existing techniques require the use of an enclosure whichis-separated off and sealed off from the normal environmentalatmosphere. This state of affairs is found inter alia in nuclearengineering, for handling dangerous articles which may emit radioactiveparticles or poisonous gases in a special chamber, and for treatingpatients suffering from very infectious diseases; in

the latter case the hermetic enclosure is at a negativepressure inrelation to atmosphere since the contamination protection is beingprovided for the atmosphere. On the other hand, some forms of medicaltherapy call for complete biological protection of the environment froma hermetic cell or the like containing a patient. One of the commonestforms of the latter case is the one in which, after a patient hastemporarily become hypersusceptible to bacteriological contamination, heis placed for a time in an enclosure which is at a slightly higherpressure than atmosphere, to ensure that any leaks occurring are alwaysfrom inside the enclosure to atmosphere, so that no pathogenic agentscan enter the treatment cell or chamber or the like.

However, so that there may be access to facilitiesin enclosures of thiskind and so that essential work may be carried out therein, a commontechnique is to use protective clothing not unlike a diving suit andpermanently connected to the superficial area of the hermetic enclosurealong an orifice in the walls thereof. Conventionally, protectiveclothing of this kind comprises a hermetic garment for covering thebody, head, arms and hands; the hands are also placed in removablerubber or plastics gloves hermetically secured to the arms of thehermetic or insulating garment; consequently, after he has put on theprotective clothing the operator canearry out the various operationsneeded inside the enclosure I Protectiveclothing of the, kind justoutlined is very disadvantageousin cases where the operator has to workin a hermetic enclosure at a slightly higher pressure than atmosphericpressure, since even a pressure slightly above atmospheric pressureforces the protective clothing into intimate engagement withtheoperator's body and thus makes it very difiicult for the operator to putthe clothing on.

lt is precisely theaim of this invention to provide protective clothingwhich can be used for working in a hermetic enclosure or cell or chamberor the like and which makes it possible, when the operator works in anoverpressure chamber, to extend or unfold the clothing readily and toprovide satisfactory working conditions bodiments the latter can beembodied by a better matea permanent leak from the inflatable zone tothe inside of the protective clothing exists by way of permeable m'eans'disposed .on the inner wall, and means for permitting and adjusting therate of leakage flow from inside the protective clothing to the ambientatmosphere are provided at at least one place of the hermetic garment,preferably near the waist or at the back. According to the invention,therefore, injecting a breathable gas mixture into the inflatable zonehastwo purposes to inflate the protective clothing and to supply theoperator with breathable gas, since the clothing inner wall is formedover all or some of its surface with porous zones through whichsufficient gas to enable the operator to breathe can leak into theinside of the clothing.

The usefulness of a facility of this kind will be clearly apparent;thanks to the inflatable zone, the protective clothing can be stiffenedeven in a slight overpressure atmosphere and thus facilitate theoperators work, since his body is not in intimate engagement with theentire superficial area of the inner wall; in some emrial than theplastici'zed films normally used; in some cases, the clothing inner wallcan be embodied by close-woven permeable cloth.

According to another feature of the invention, inflation of theinflatable zone between the inner and outer walls is limited .by the twowalls being interconnected at a number of places, for instance, by weldlines distributed over the garment surfaces.

Porosity of the inner wall can be provided in various ways, alwaysprovided that the perviousness of the inner wall to the breathable gasresponsible for inflation is sufficient to produce a pressure loss highenough for the operator to breathe at a pressure very slightly above thepressure in the enclosure.

In a first variant, the porous inner wall of the garment consistsentirely of a closewoven cloth pervious to the respiratory gasresponsible for inflation. In a second variant, the garment inner wallcomprises a hermetic material, such as a 'plasticized film or aplastics-coated cloth, overmost of its superficial area but in someregions has cloth zones for the local passage of the respiratory gasresponsible for inflation. In a third-variant, the garment inner wall ishermetic and perviousness to the respiratory gas responsible forinflation is by way of a number of apertures. Advantageously in the twolatter variants, the local leakage zones for the respiratory gas aredisposed under the armpits, at the wrists, near the neck, on the thighsand at the ankles i.e., at the places usually associated withtheheaviest transpiration.

According to the invention, the clothing interior must communicate byway of a slight and controlled leak with the environmental atmospherefor evacuation thereto of the respiratory gases and of the operator'ssweat. There are various ways and means of achieving this according tothe invention. For instance, communication between the inside of theclothing and the ambient atmosphere can be by way of a calibrated valvedisposed on the garment inner wall, the valve being calibrated tomaintain the internal pressure at the required value very slightlyabovethe pressure in the chamber. This solution is very useful, moreparticularly when the protective clothing covers the entire body and isclosed hermetically thereon. More particularly in cases in which theprotective clothing covers only the top of the body outside the chamber,limitation of the rate of flow of the breathable gas responsible forinflation as necessary to keep the inside of the clothing at a slightlyhigher pressure than the enclosure can be achieved by means of a bib orapron which is welded to the clothing and which engages around theoperators hips and has an elastic band at the bottom. In this embodimentthe rate of leakage flow can be'controlled by varying the tightness withwhich the elastic band grips the operator. A similar system i.e., anapron welded to the clothing and having an elastic band may also beadvantageous in cases where protective clothing which completely coversthe whole body is in two separate parts i.e., a blouse-like part andtrousers. In this case the trouser band or belt can perform the functionof the elastic band described with reference to the previous embodiment.

In addition to its chief advantage provided by inflation of thestructure, the protective clothing according to the invention has thetwo following advantages;

the breathable gas responsible for inflation can be supplied to thebetween-walls space at a low pressure because the area on which thepressure is operative is so large. In practical terms, this means thatthe inflatable zone can be supplied by means of an ordinary fan and nocompressor is needed. Also, since the inflatable zone can, if required,be supplied with biologicallyfiltered respiratory gases, there is norisk of contamination of the hermetic enclosure should the garment outerwall be accidentally torn.

Although the protective clothing according to the invention is of usemore particularly for working in an enclosure in which the pressureisabove the environmental atmosphere, it can also be very useful forworking in a hermetic enclosure in which the pressure is below thepressure of the ambient atmosphere. In negativepressure working theoperator breathes at a pressure below the pressure of the ambientatmosphere, and the consumed respiratory gases must leak away directlyfrom inside the clothing to the inside of the hermetic enclosure, forinstance, by way of a valve providing a direct communication between theinside of the clothing with the inside of the enclosure. In this case,therefore, there must be no leakage from atmosphere to inside theclothing, and so the clothing must contain the operators body'-- or thatpart thereof covered by the clothing in a very sealing-tight manner.There are various ways of achieving this state of affairs, inter alia bymeans of sticky tapes. One advantage of operating in this way is thatvery considerably negative pressures can be used, the only limitationbeing physiological and not mechanical, for inflation of the inner zoneconsiderably offsets the risks of the protective clothing bursting dueto the negative pressure. The invention will in any case be betterunderstood from the following non-limitative description of threeembodiments, reference being made to the accompanying drawings wherein:

FIG. I is a basic diagram serving to give an idea of pressuredistribution in protective clothing for protecting just the top half ofthe operator working in an enclosure at a slightly higher pressure thanthe ambient atmosphere;

FIG. 2 is a detailed view of the protective clothing of FIG. 1;

FIG. 3 shows an alternative embodiment of the protective clothingaccording to the invention for use in an overpressure chamber, theclothing being a full suit which fully covers the operators whole body,and

FIG. 4 is a pressure distribution diagram for a halfsuit for working inan enclosure at a pressure slightly below the ambient atmosphere.

Referring to FIG. 1, it is required to protect a hermetic enclosure orchamber or cell or the like 1 from possible external contamination; tothis end, chamber 1 is pressurized to e.g. about +15 mm water columnabove the outside pressure. Wall 2 of chamber 1 is formed with anaperture 3 around which outer wall 4 of protective clothing 5 engageshermetically; according to the invention, wall 4 forms an extension ofwall 2 without any break in sealing tightness. The clothing 5 is ahalf-suit which covers the top half of an operator 6 and comprises adouble-walled garment comprising the outer wall 4 previously mentionedand an inner wall 7. Between the two walls 4, 7 is an inflatable zonewhich a supply line 8 connects to the outside. Suit 5 also includes arigid transparent helmet 9 which bears in sealing-tight manner on theoperator's shoulders, rubber gloves 10 and, at the bottom of the bust,an apron 11 which extends the inner wall downwardly at the base of thebust and an elastic band 12 clamps around the operators hips. Accordingto the invention, inner wall 7 has a number of porous zones l3l7 throughwhich there can be some gas flow between the inflatable zone and theinside of the clothing.

Pressure distribution throughout the system is as follows: if thechamber 1 is at a pressure of e.g. +15 mm water column relatively to theambient atmosphere, respiratory gases are introduced through line 8 intothe intermediate zone at a pressure of +40 mm water column; thispressure, which is appreciably higher than the pressure in chamber 1,immediately inflates and stiffens the protective clothing, thus enablingthe operator to don it readily. Also, there can be a controlled leakageof the respiratory gases through the porous zones l3l7 into the insideof the clothing 5 where the pressure is about +18 mm water column.Exhaled gases and the operators sweat can leak away to atmosphere viathe joint provided by the elastic band on the operators hips; as anindication, this rate of flow is of the order of from 10 to 20 m /h.

FIG. 2 shows the various parts of FIG. 1 in greater detail. Moreparticularly apparent is the known twogroove system 18 for a hermeticand releasable securing of the gloves 10 to the sleeves of the clothing5. Also visible are weld lines 19 along which, according to theinvention, the clothing inner and outer walls are welded together tolimit expansion of the intermediate inflatable zone. Also visible inFIG. 2 is a weld line 20 along which the apron I1 is secured to thedouble walls of the actual garment.

FIG. 3 shows an alternative form of protective clothing according to theinvention for use in a chamber 1 at a higher pressure than atmosphere.In this embodiment the protective clothing 5 completely envelops theoperators body and the clothing outer wall 4 is extended by a flexiblewall 21 bounding an access corridor or passage or the like 22 throughwhich the operator can get into the clothing and which is deformable sothat he can move about in the chamber 1. Means which are not shown inFIG. 3 can, if necessary, be provided to stiffen the passage 22 againstthe overpressure tending to compress the walls.

in this embodiment the clothing 5 closes on the operators back by adiaphragm 23; the same is closed nonhermetically at a place 24 which isdisposed in the passage 22 and through which the exhaled gases leak awayto atmosphere.

In the example shown in FIG. 4 the chamber 1 is at a negative pressureof something like -20 mm water column relatively to atmosphere. Theprotective clothing 5 is closed hermetically, e.g. by means of adhesivetapes, along the line 12 around the operators hips; the respiratory gasresponsible for inflation is introduced through line 8 at a pressure of+20 mm water column, the operator breathes at a pressure ofsubstantially l 5 mm water column, and in this embodiment exhaled airleaks away to the hermetic chamber 1 through a valve 25, whichaccordingly provides direct communication between the inside of theclothing and the chamber 1 via the inner and outer walls of the garment.The advantage of a system of this kind over conventional single-walledclothing is that the negative pressure can be taken to the limit ofphysiological resistance without any risk of the clothing exploding,since the pressure variation between the inside of the clothing and theinside of the chamber 1 is always kept at a very reduced value.

I claim:

1. Protective clothing for an operator working in a hermetic enclosureat a positive pressure to the ambient atmosphere comprising awall forthe enclosure, a

hermetic garmentforming an integral part of the enclosure wall andhaving a transparent helmet to protect the head and interchangeablegloves,

two walls for said garment including an inner wall in contact with theoperatorand an outer wall common to the enclosure wall, the two wallscooperating to bound a'n inflatable zone;

permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, andmeans for adjusting the rate of leakage flow from inside the protectiveclothing to the ambient atmosphere are provided 'on the hermeticgarment.

2. Protective clothing according to claim 1 said permeable meanspermitting permanent leakage from the inflatable zone to the inside ofthe protective clothing being a porous inner wall.

3. Protective clothing according to claim 1 wherein the means forpermitting and adjusting the rate of leakage flow from inside theprotective clothing to the ambient atmosphere is a calibrated valvedisposed on the inner wall and through which the interior of theprotective clothing communicate with the ambient atmosphere.

4. Protective clothing accordingto claim 1 wherein the means forpermitting and adjusting the rate of leakage flow from inside theprotective clothing to the ambient atmosphere includes an apronconsisting of a downward extension of the inner wall from a point belowthe said inflatable zone and adapted to surround the base of the bust ofthe operator, and resilient clamping means adjacent the bottom of saidapron for clamping the apron to the operators hips.

5. Protective clothing according to claim 1 wherein the means permittingpermanent leakage from the inflatable zone to outside the protectiveclothing are apertures in the inner wall.

6. Protective clothing according to claim 5 wherein the apertures aredistributed in regions disposed in the areas of the garment adjacent thearmpits, the wrists, the neck, the thighs, and the ankles of theoperator.

7. Protective clothing for an operator working in a hermetic enclosureat a negative pressure to the ambient atmosphere, comprising a wall forthe enclosure, a hermetic garment forming an integral part of theenclosure wall and having a transparent helmet to protect the head andinterchangeable gloves,

two walls for said garment including an inner wall in contact with theoperator and an outer wall common to the enclosure wall, the two wallscooperating to bound an inflatable zone;

permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, andmeans for adjusting the rate of leakage flow from inside the protectiveclothing to inside the hermetic enclosure are provided on the hermeticgarment.

8. Protective clothing for an operator working in a hermetic enclosureat a positive pressure to the ambient atmosphere comprising a wall forthe enclosure, a hermetic garment forming an integral part of theenclosure wall having a transparent helmet to protect the head andinterchangeable gloves, two walls for said garment including an innerwall in contact with the operator and an outer wall common to theenclosure wall, the'two wall co-operating to bound an inflatable zone,permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, meansfor adjusting the rate of leakage flow from inside the protectiveclothing to the ambient atmosphere on the hermetic garment saidpermeable means being a porous inner wall, said p0- rous inner wallbeing a closewoven cloth perveous over its entire superficial area tothe respiratory gas responsible for inflation.

9. Protective clothing for an operator working in a hermetic enclosureat a positive pressure to the ambient atmosphere comprising a wall forthe enclosure, a hermetic garment forming an integral part of theenclosure wall and having a transparent helment to protect the head andinterchangeable gloves, two walls for said garment including an innerwall in contact with the operator and an outer wall common to theenclosure wall, the two walls co-operating to bound an inflatable zone,permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, andmeans for adjusting the rate of leakage flow from inside the protectiveclothing tory gas responsible for inflation.

10. Protective clothing according to claim 9 wherein the cloth zones aredisposed in the areas of the garment adjacent the armpits, the wrists,the neck, the thighs,

and the ankles of the operator.

1. Protective clothing for an operator working in a hermetic enclosureat a positive pressure to the ambient atmosphere comprising a wall forthe enclosure, a hermetic garment forming an integral part of theenclosure wall and having a transparent helmet to protect the head andinterchangeable gloves, two walls for said garment including an innerwall in contact with the operator and an outer wall common to theenclosure wall, the two walls co-operating to bound an inflatable zone;permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, andmeans for adjusting the rate of leakage flow from inside the protectiveclothing to the ambient atmosphere are provided on the hermetic garment.2. Protective clothing according to claim 1 said permeable meanspermitting permanent leakage from the inflatable zone to the inside ofthe protective clothing being a porous inner wall.
 3. Protectiveclothing according to claim 1 wherein the means for permitting andadjusting the rate of leakage flow from inside the protective clothingto the ambient atmosphere is a calibrated valve disposed on the innerwall and through which the interior of the protective clothingcommunicate with the ambient atmosphere.
 4. Protective clothingaccording to claim 1 wherein the means for permitting and adjusting therate of leakage flow from inside the protective clothing to the ambientatmosphere includes an apron consisting of a downward extension of theinner wall from a point below the said inflatable zone and adapted tosurround the base of the bust of the operator, and resilient clampingmeans adjacent the bottom of said apron for clamping the apron to theoperator''s hips.
 5. Protective clothing according to claim 1 whereinthe means permitting permanent leakage from the inflatable zone tooutside the protective clothing are apertures in the inner wall. 6.Protective clothing according to claim 5 wherein the apertures aredistributed in regions disposed in the areas of the garment adjacent thearmpits, the wrists, the neck, the thighs, and the ankles of theoperator.
 7. Protective clothing for an operator working in a hermeticenclosure at a negative pressure to the ambient atmosphere, comprising awall for the enclosure, a hermetic garment forming an integral part ofthe enclosure wall and having a transparent helmet to protect the headand interchangeable gloves, two walls for said garment including aninner wall in contact with the operator and an outer wall common to theenclosure wall, the two walls cooperating to bound an inflatable zone;permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective clothing, andmeans for adjusting the rate of leakage flow from inside the protectiveclothing to inside the hermetic enclosure are provided on the hermeticgarment.
 8. Protective clothing for an operator working in a hermeticenclosure at a positive pressure to the ambient atmosphere comprising awall for the enclosure, a hermetic garment forming an integral part ofthe enclosure wall having a transparent helmet to protect the head andinterchangeable gloves, two walls for said garment including an innerwall in contact with the operator and an outer wall common to theenclosure wall, the two wall co-operating to bound an inflatable zone,permeable means disposed on the inner wall providing a permanent leakfrom the inflatable zone to the inside of the protective cloThing, meansfor adjusting the rate of leakage flow from inside the protectiveclothing to the ambient atmosphere on the hermetic garment saidpermeable means being a porous inner wall, said porous inner wall beinga closewoven cloth perveous over its entire superficial area to therespiratory gas responsible for inflation.
 9. Protective clothing for anoperator working in a hermetic enclosure at a positive pressure to theambient atmosphere comprising a wall for the enclosure, a hermeticgarment forming an integral part of the enclosure wall and having atransparent helment to protect the head and interchangeable gloves, twowalls for said garment including an inner wall in contact with theoperator and an outer wall common to the enclosure wall, the two wallsco-operating to bound an inflatable zone, permeable means disposed onthe inner wall providing a permanent leak from the inflatable zone tothe inside of the protective clothing, and means for adjusting the rateof leakage flow from inside the protective clothing to the ambientatmosphere on the hermetic garment said permeable means being a porousinner wall, the inner wall being a hermetic material having in someregions cloth zones for the local passage of the respiratory gasresponsible for inflation.
 10. Protective clothing according to claim 9wherein the cloth zones are disposed in the areas of the garmentadjacent the armpits, the wrists, the neck, the thighs, and the anklesof the operator.